A long time ago, I tried to make an uncommon dual land cycle by finding a restriction more tied to creatures (it was for a Pokémon set, I believe, which was very creature-centric). I reached this condition, but it was amazingly weak, so instead of just adding two colors it got to add any.

This new fancy ability word that just came out reminded me of the card.

It still creatures a strange pattern, because normally a creature-centric deck (especially if focused on attacking) wants the mana to cast said creatures, not later. But it's not impossible to have a modest manabase for your early drops and then follow it up with color-intensive spells. Maybe you only have white creatures in your one-drops and other multicolored creatures in 2 and 3.